Ethernet virtual private network (EVPN) using an internet protocol version 6 segment routing (SRv6) underlay network and SRv6-enhanced border gateway protocol (BGP) signaling

Abstract

In one embodiment, Ethernet Virtual Private Network (EVPN) is implemented using Internet Protocol Version 6 (IPv6) Segment Routing (SRv6) underlay network and SRv6-enhanced Border Gateway Protocol (BGP) signaling. A particular route associated with a particular Internet Protocol Version 6 (IPv6) Segment Routing (SRv6) Segment Identifier (SID) is advertised in a particular route advertisement message of a routing protocol (e.g., BGP). The SID includes a locator of a particular router and a function encoding representing a particular EVPN end function of the particular router, with the particular SID including a routable prefix to the particular router. The particular router receives a particular packet including the particular SID; and in response, the particular router performs the particular EVPN end function on the particular packet. In one embodiment, the particular packet includes a Segment Routing Header (SRH) including the particular SID as the currently active SID.

What is claimed is: 
     
       1. A method, comprising:
 advertising, in a network via a particular route advertisement message of a routing protocol, a particular route associated with a particular Internet Protocol Version 6 (IPv6) Segment Routing (SRv6) Segment Identifier (SID), with the particular IPv6 SID including a locator of a particular router and a function encoding representing a particular Ethernet Virtual Private Network (EVPN) Segment Routing end function of the particular router, with the particular IPv6 SID being an IPv6 routable address of the particular router; 
 receiving, by the particular router, a particular IPv6 packet including the particular IPv6 SID as the IP Destination Address of the IPv6 Packet; and 
 in response to said received particular packet including the particular IPv6 SID, the particular router performing the particular EVPN Segment Routing end function on the particular IPv6 packet; 
 wherein the routing protocol is Border Gateway Protocol; and 
 wherein the particular route advertising message includes an implicit null label in each of one or more BGP Multiprotocol Label Switching-based (MPLS-based) EVPN label fields identifying that BGP MPLS-based EVPN is not supported by the particular router while SRv6 EVPN is supported by the particular router as identified in the particular route advertisement message. 
 
     
     
       2. The method of  claim 1 , wherein the particular IPv6 packet includes a Segment Routing Header (SRH) including the particular IPv6 SID as the currently active SID. 
     
     
       3. The method of  claim 1 , comprising:
 receiving an advertisement of the particular route being associated with the particular IPv6 SID by an ingress router in the network; 
 receiving an Ethernet frame by the ingress router; 
 encapsulating the Ethernet frame into the particular IPv6 packet by the ingress router; and 
 sending the particular IPv6 packet into the network by the ingress router; 
 wherein said performing the particular EVPN Segment Routing end function on the particular IPv6 packet includes decapsulating the Ethernet frame from the particular IPv6 packet and sending the Ethernet frame from the particular router. 
 
     
     
       4. The method of  claim 3 ,
 wherein the particular router and a second router in the network are multihomed to a same Ethernet segment or node; 
 wherein the particular IPv6 SID includes a particular argument including a representation of a particular Ethernet Segment Identifier (ESI); and 
 wherein said sending the Ethernet frame from the particular router includes sending the Ethernet frame from the particular router on one or more corresponding Layer 2 output interfaces except the Layer 2 output interface identified by the particular ESI. 
 
     
     
       5. The method of  claim 3 ,
 wherein the particular router and a second router in the network are multihomed to a same Ethernet segment or node; 
 wherein the particular IPv6 SID includes a particular argument including a representation of a particular Ethernet Segment Identifier (ESI); and 
 wherein said performing the particular EVPN Segment Routing end function on the particular packet includes determining not to send the Ethernet frame from a Layer 2 output interface identified by the particular ESI. 
 
     
     
       6. The method of  claim 5 , wherein the second router and the ingress router are the same routers. 
     
     
       7. The method of  claim 1 , wherein the particular route advertising message advertises a BGP route type 1, 2, 3, or 5, and associated with a particular SRv6-VPN Type Length Value (TLV) including the particular IPv6 SID. 
     
     
       8. The method of  claim 7 , wherein the particular route advertising message identifies that SRv6 EVPN is supported by the particular router as identified by the SRv6-VPN TLV. 
     
     
       9. The method of  claim 1 , wherein the particular IPv6 SID is a 128-bit IPv6 address. 
     
     
       10. A method, comprising:
 receiving, by an ingress router in a network, a particular route advertisement message of a routing protocol advertising a particular route associated with a particular Internet Protocol Version 6 (IPv6) Segment Routing (SRv6) Segment Identifier (SID), with the particular IPv6 SID including a locator of a particular router and a function encoding representing a particular Ethernet Virtual Private Network (EVPN) Segment Routing end function of the particular router, with the particular IPv6 SID being an IPv6 routable address of the particular router; 
 receiving a particular Ethernet frame by the ingress router; 
 determining the particular IPv6 SID should be associated with the Ethernet frame; 
 encapsulating the particular Ethernet frame in a particular IPv6 packet including the particular IPv6 SID by the ingress router; and 
 sending the particular IPv6 packet from the ingress router; 
 wherein the routing protocol is Border Gateway Protocol; and 
 wherein the particular route advertising message includes an implicit null label in each of one or more BGP Multiprotocol Label Switching-based (MPLS-based) EVPN label fields identifying that BGP MPLS-based EVPN is not supported by the particular router while SRv6 EVPN is supported by the particular router as identified in the particular route advertisement message. 
 
     
     
       11. The method of  claim 10 , comprising:
 receiving the particular IPv6 packet by the particular router; and 
 in response to said received particular IPv6 packet including the particular IPv6 SID, the particular router performing the particular EVPN Segment Routing end function identified in the particular IPv6 packet, which includes decapsulating the Ethernet frame from the particular IPv6 packet and sending the Ethernet frame from the particular router. 
 
     
     
       12. The method of  claim 11 ,
 wherein the particular router and a second router in the network are multihomed to a same Ethernet segment or node; 
 wherein the particular IPv6 SID includes a particular argument including a representation of a particular Ethernet Segment Identifier (ESI); and 
 wherein said performing the particular EVPN Segment Routing end function on the particular IPv6 packet includes determining not to send the Ethernet frame from a Layer 2 output interface identified by the particular ESI. 
 
     
     
       13. The method of  claim 10 , wherein the particular route advertising message advertises a BGP route type 1, 2, 3, or 5, and associated with a particular SRv6-VPN Type Length Value (TLV) including the particular IPv6 SID. 
     
     
       14. The method of  claim 13 , wherein the particular route advertising message identifies that SRv6 EVPN is supported by the particular router as identified by the SRv6-VPN TLV. 
     
     
       15. An apparatus, comprising:
 one or more hardware interfaces sending and receiving packets in a network; and 
 one or more network processors with memory associated therewith; 
 wherein the apparatus performs packet processing operations including segment routing-capable (SR-capable) packet processing operations, with said packet processing operations including: 
 advertising, via a particular route advertisement message of a routing protocol, a particular route associated with a particular Internet Protocol Version 6 (IPv6) Segment Routing (SRv6) Segment Identifier (SID), with the particular IPv6 SID including a locator of the apparatus and a function encoding representing a particular Ethernet Virtual Private Network (EVPN) end function of the apparatus, with the particular IPv6 SID being an IPv6 routable address of the apparatus; 
 receiving a particular IPv6 packet including the particular IPv6 SID; and 
 performing the particular EVPN Segment Routing end function on the particular packet in response to said received particular IPv6 packet including the particular IPv6 SID; 
 wherein the routing protocol is Border Gateway Protocol; and 
 wherein the particular route advertising message includes an implicit null label in each of one or more BGP Multiprotocol Label Switching-based (MPLS-based) EVPN label fields identifying that BGP MPLS-based EVPN is not supported by the apparatus while SRv6 EVPN is supported by the apparatus as identified in the particular route advertisement message. 
 
     
     
       16. The apparatus of  claim 15 , wherein the particular route advertising message advertises a BGP route type 1, 2, 3, or 5, and associated with a particular SRv6-VPN Type Length Value (TLV) including the particular IPv6 SID. 
     
     
       17. The apparatus of  claim 16 , wherein the particular route advertising message identifies that SRv6 EVPN is supported by the apparatus as identified by the SRv6-VPN TLV including the particular IPv6 SID.